Light-pipe is a common light-homogenizing element, which is used to homogenize light beam. The light-pipe includes a tube which is covered with a reflection layer. When enters the light-pipe, the light beam is reflected repeated in the tube, therefore the enterned light beam is homogenized. In the optical-mechanical system, the light beam from the light source optical structure first enters into the light-pipe for homogenizing and then enters into the digital micromirror device (DMD) illuminating optical path. When the light-pipe deviates from a predetermined position or the light-outputting position of the light source optical structure is adjusted, the position of the light-pipe needs to be adjusted by using the light-pipe adjusting apparatus to ensure light-homogenizing effect.
Referring to FIG. 1, the light-pipe adjusting apparatus in the related art includes a pipe body 101, an adjusting system, and a light-pipe 102. The adjusting system includes an elastic member 103 and a bolt 104. Herein, the elastic member 103 is provided in the pipe body 101, the bolt 104 is connected to a screw hole of the pipe body 101 and can extend into the pipe body 101 along a radial direction of the pipe body 101, the bolt 104 is provided in the same direction as the elastic member 103, and the light-pipe 102 is inserted in the pipe body 101 and sandwiched between the elastic member 103 and the bolt 104. The light-pipe 102 can be positioned by the clamping action between the bolt 104 and the elastic member 103, and the bolt 104 can radially extend and contract by rotating the bolt 104, so as to adjust the relative position of the light-pipe 102 and the pipe body 101, and further adjust the position of the light-pipe 102 in the optical path, thereby ensuring the light-homogenizing effect.